In an interview, McCaskill simply smiled when she was asked if Obama's choice of Cape Girardeau for Tuesday's stop had some particular significance. It's the hometown of the nation's most prominent conservative commentator, Rush Limbaugh, who has been encouraging Republicans to cross over in some state Democratic primaries and vote for Clinton.

Missouri voters cast primary ballots Feb. 5. But voters in Kentucky will have their primary May 27, and broadcast media serving the Cape Girardeau area also serves most of western Kentucky.

The event will not be a campaign rally but a serious discussion on issues ranging from food and gas prices to mortgage and credit issues, among others, the source said.

"Barack Obama understands the economic conditions and the challenges the Bush administration has presented to middle-class families have been unfortunate, to say the least," the Democratic source said.

But will anyonereally be fooled? After the way Rush's Operation Chaos has become a central element of the primary season, why would voters believe Obama just happened to pick Limbaugh's hometown to talk about the economy?

Expect a major helping of class warfare and partisan attacks in Cape Girardeau tomorrow. If he didn't think there were points to be scored, why else would Obama visit?

UPDATE: In the opening segment of today's show, Limbaugh said he thinks this is Obama's way of avoiding the drubbing he's about to take in tomorrow's West Virginia primary. In addition, he suggested Obama take the Rush Limbaugh Tour offered there.